pdl: replace helpers with new ‘types’ module

This replaces a few helpers with a new ‘Integer’ struct. This struct
implements ‘ToTokens’ and gives convenient access to the its width.

Test: atest pdl_tests pdl_inline_tests
(cherry picked from https://android-review.googlesource.com/q/commit:1b2efbc194acc452898a4e8bed4265d948a5790e)
Merged-In: Ibe2521367e92207969657f59b1cc5b6f5754a6f1
Change-Id: Ibe2521367e92207969657f59b1cc5b6f5754a6f1